Carpet cleaning systems that utilize pre-heated water or "steam" to clean carpets are generally well known in the art. Typically these systems direct a source of water through a pump driven by an engine. The pump then directs the water through a safety valve and from there to a heat exchanger. Heated water exits the heat exchanger, passes through a thermostat, and from there the water is directed to a hand held carpet cleaning wand.
The wand houses a trigger mechanism that controls the fluid flow through the wand and out through an exhaust port formed in the end thereof. The fluid is directed downwardly into the carpet being cleaned. The wand also forms a vacuum suction inlet port which directs residual waste water back to a waste water recovery tank that is kept under a vacuum by an engine driven blower or vacuum pump.
Larger carpet cleaning systems are generally mounted upon vehicles and connected to the wand via long hoses. Although the vehicle mounted heater is generally capable of increasing the temperature of the water to be used in the cleaning process to a desire level, the use of such long hoses may cause an appreciable amount of the heat contained within the water to be lost as the water travels through the hoses. Thus, the temperature of the water at the wand, where cleaning is effected, may be lower than desired in such instances. Furthermore, many of the smaller or home carpet cleaning systems utilize heaters which are incapable of adequately heating the water. Thus, although the smaller units are portable and therefore convenient to use, they may not be as effective as desired.
As such, it is desirable to provide a means for increasing the temperature of water flowing through the lines which interconnect the carpet cleaning unit and the wand.